Electric lock and alarm apparatus.



0. NITSCH. ELECTRIC LOOK AND ALARM APPARATUS. APPLICATION FILED JAN. 29,1914.

1,100,681, Patented June 16,1914.

COLUMBIA PLANouRAPH CO..WASHINGTDN, D. c.

UNITED STATES PATENT OFFICE.

OTTO NITSCH, OF HARBURG-ON-THE- ELBE, GERMANY.

ELECTRIC LOCK AND ALARM APPARATUS.

To all whom it may concern Be it known that I, Or'ro Nrrsorr, a subjectof the King of Prussia, and resident of 2 Wilsdorferstrasse, Harburg onthe-Elbe, in the Empire of Germany, have invented a new and usefulImproved Electrical Lock and Alarm Apparatus, of which the following isa specification.

The present invention relates to an im proved electric safety device fordoor locks in combination with a signal or alarm apparatus.

Special objects of the invention are to render more eflicient,serviceable and durable in operation safety devices of the kind referredto.

With these ends in view the invention consists in the novel combination,arrangement and adaptation of parts, all as more fully hereinafterexplained, shown in the accompanying drawings and finally set out in theappended claim.

In the annexed drawing is shown diagrammatically one mode of carryinginto practice my invention.

My invention being suitable for door locks of any desired type whichemploys a slidable bolt for locking the door, I have deemed itunnecessary to illustrate the door.-

lock, but have restricted the illustration to the slidable bolt, whichis essential in the combination constituting my invention.

The slidable bolt a, besides the ordinary arresting mechanism providedin the lock case, is under the influence of an accessory lockingarrangement formed by the armature b of-an electromagnet 0 Thisaccessory locking arrangement is rendered effective by means of a nose 0on the armature Z2 entering a notch (Z or e of the slidable bolt a, thenotches d and 0 being provided in such co-relative positions that theslidable bolt on assumes its locking position when the nose 0 enters thenotch d and that it assumes its inoperative position when the nose 0enters the notch e.

The armature Z) is pivotally attached to the lock case by means of thepin f in such a position, that it separates from the notch (Z or arespectively on being energized, thus liberating the bolt 0; which canthen be moved either in one or the other direction.

The electromagnet 0 is in conductive connection with the source ofelectricity g by means of suitably arranged and protected line wires,the electric circuit containing Specification of Letters Patent.

Application filed January 29, 1914.

Patented June 16, 1914.

Serial No. 815,577.

also the cut out it and the push-button switch 2'. A second push-buttonswitch 7 is arranged in the proximity of the door lock at the outside ofthe door, in order to enable the door lock to be opened from outside.This second puslrbutton switch is is fitted for two contacts Z and m sothat on its actuation the alarm bell n rings previous to the liberationof the slidable bolt a from the lever armature b. The contact Z closesan electric circuit over the line wire 0, the bell n, the line wire 2),the source of electricity 9 and the line wire (7 and thus actuates thealarm bell a. When the push-button 70 reaches the contact m an electriccircuit is closed, which contains the electromagnet 0 this electriccircuit being constituted by the source of electricity g, the line wireq, the push-button 7c, the electromagnet 0 the line wire 8 and the cutout h. On thus energizing the electromagnet c the armature b isattracted and in consequence thereof the slidable bolt 0; is disengagedfrom the nose 0, so that the door lock can be opened.

When it is required to open the locked door from inside, the push-buttonc in the proximity of the source of electricity 9 has to be actuated.The electromagnet c is in this case energized by the current flowingthrough the circuit constituted by the source of electricity g,push-button i, line wire 1", electromagnet 0 line wire 8 and cut out it.

The electromagnet 0 thus attracting the armature b, the door can beopened and locked again. The alarm bell n is also sounded when openingthe locked door from inside but by only one electric circuit, which iscaused by the armature Z) touching the contact 25. This electric circuitis closed over the source of electricity 9, the pushbutton 41, the linewire a", the electromagnet 0 the contact 25, the line wire 0, the alarmbell n and the line wire 29.

If an unauthorized person attempts to open the locked door from outsideand, to prevent the alarm apparatus from being sounded, tries to evadethe push-button 72 by conductively connecting the contacts a and m, sayby means of a piece of wire, the alarm bell a still sounds by virtue ofthe electric circuit closed over the source of electricity g, line wireg, wire connecting a and m at the push-button 7c, armature contact t,line wire 0, alarm bell n and line wire 22. This actuation of the alarmapparatus is independent from the cut out it.

The improved locking and alarm arrangement affords a reliable insuranceagainst the opening of locked doors by unauthorized persons.

What I do claim as my invention, and desire to secure by Letters Patent,is:

The combination with the bolt of a door lock, of an electromagnet, apivoted arma ture lever, a nose thereon adapted to engage in a notch inthe bolt both when thrown and when retracted, a spring contact touchingthe armature lever when same is attracted, line wires separately leadingfrom the electromagnet, the armature lever and the spring contact to acommon source of electricity, an alarm bell, a cut out and a pushbuttonpreferably arranged in close proximity to the source of electricityinside the door and in conductive connection with the electromagnet, thearmature lever and the spring contact, a push-button outside the doornear the door lock, two contacts for this push-button arranged inconductive connection with the source of electricity and theelectromagnet for releasing the door lock, so that the alarm bell soundseven if the ordinary alarm circuit is intentionally disturbed previousto actuating the push-button for electrically releasing the bolt of thedoor lock, substantially as described and shown and for the purposes setforth.

In witness whereof I have hereunto signed my name this 17th day ofJanuary 1914, in the presence of two subscribing wltnesses.

OTTO NITSCIL lVitnesses FRIEDRICH MANHISER, ERNEST H. L. MUMMENHOFF.

Copies of this patent may be obtained foi five cents each, by addressingthe Commissioner of latents, Washington, D. (3.

